Hydrogen went out of fashion with the Hindenburg, the giant German airship which burst into flames in 1937. But chilled to -253C, and used as a fuel, it is suddenly all the rage once again. Britain's first hydrogen fuel station opens today in Birmingham, and though it is only a small experimental site, powering a fleet of vehicles at the city's university, it is a sign of things to come. More hydrogen stations are planned for London, where buses may soon run on the fuel, while the first production hydrogen cars, from BMW and Honda, have gone on sale. Morgan, the sports car maker more commonly associated with tweed, plus fours and British racing green paint, unveiled a hydrogen-powered concept car at last month's Geneva motor show. Nor is the fuel confined to four wheels: a London theatre recently installed a small hydrogen fuel cell to power lights. Hydrogen's great advantage is that it causes no pollution - when combined with atmospheric oxygen in a fuel cell it produces clean water and electric power. This would make it the perfect fuel for a post-carbon future were it not for the awkward fact that producing it requires large amounts of electricity, and with it lots of pollution. That has led critics to complain that it is not really a green fuel at all - and they have a point. But combined with renewable (or nuclear) electricity, hydrogen could have a future, if a way can be found to distribute it. As things stand, Britain's hydrogen pioneers will have to head to Birmingham every time they want to fill up.